Working with big numbers
You can set the 3D View far clipping distance in the properties panel (press N in the 3D view to toggle it),
and/or
the Camera far clipping distance in the Lens section of the Camera tab:



By the way, it's limited to maximum 10 000 units (or 10Km), so I don't think it'll works nice with objects having scale in millions.

You should consider scaling down the objects by a factor you know (say, *0.001):


select all objects (press A)
press S, then .001
then, left click to confirm.


If you want to control the scale center point in order to keep relative coordinates of the objects, you can place you 3D cursor where you want and choose 3D cursor pivot center before scaling your objects.